Examining the effects of nano iron oxide on physical and mechanical characteristics of rubberized concrete

Utilizing waste rubber tires as rubber aggregate (RA) in concrete presents an environmentally sustainable solution, addressing the challenge of depleting natural aggregate (NA) resources. In this innovative approach to construction practices, rubberized concrete (RC) is created with RA, offering eco-friendly traditional concrete. Iron oxide (IO) is added to RC to improve its mechanical and physical characteristics even more. Through a comprehensive experimental study, evaluations of workability, density, compressive strength, tensile strength, and flexural strength were carried out using separate concrete samples with different ratios of IO and RA. The results demonstrated that RA introduces significant changes to the concrete's properties, at 15% fine aggregate (FA) substitution level, the concrete mixes' workability and density decreased by up to 13.46%, and 5.76% respectively. Adding RA led to reductions in compressive, tensile, and flexural strengths of concrete by 20.69%, 22.49%, and 24.16%, respectively. However, the addition of IO successfully offset these adverse consequences. Density improved even while workability decreased; at 28 days, compressive, tensile, and flexural strengths for IO mixed RC material increased by 24.82%, 6.58%, and 15.45%, respectively. The experimental results were analyzed using a variety of optimization techniques, such as response surface methodology, and analysis of variance. Further, the life cycle assessment study shows decrease CO₂ emission and little increase in embodied energy with the incorporation of IO and RA. The research findings indicate that the incorporation of RA and IO is a promising avenue for achieving environment-friendly and sustainable construction practices. The investigation of RA, FA, and IO in concrete forms the uniqueness of this research report, as no other study has been conducted that addresses all of these areas concurrently. Prior studies on the effect of RA on the regular concrete were carried out by a number of researchers, but IO was left out. As far as the authors’s knowledge, no research has been done on IO mixed RC.